1064-nm Wavelengths Research Articles

Comparison of the Effects of Four Laser Wavelengths on Medication-Related Osteonecrosis of the Jaw (MRONJ) in a Murine Model: An In Vivo Photobiomodulation Study.

Background: This study aims to investigate the effectiveness of lasers at various wavelengths in treating medication-related osteonecrosis of the jaw (MRONJ) using biochemical, clinical scoring, micro CT analysis, and histopathological methods. The study follows the ARRIVE guidelines to ensure robust and transparent research. Methods: In our study, there were 6 groups, including one SHAM group, one CONTROL group, and four experimental groups, with 8 rats in each individual group. Each rat received antiresorptive drug intraperitoneally for 4 weeks and then had the left second molar in the mandible extracted. All animals were sacrificed at the end of the 12th week. In the experimental groups, lasers at wavelengths of 405nm, 445nm, 660nm, and 808nm were applied to the animals. Parameters such as serum vitamin D levels, bone density and bone volume at the extraction site, new bone formation, dead bone count, inflammatory cell count, and epithelial regeneration were examined. Additionally, clinical scoring was conducted after sacrifice. The laser parameters included power density, area, time, fluence, and mode (continuous wave), and the light was administered using a fiber with a Gaussian profile. Statistical analyses were performed with the NCSS (Number Cruncher Statistical System) 2007 Statistical Software (Utah, USA) package program. The results were evaluated at the p<0.05 significance level. Results: According to the results obtained from our study, new bone formation in all experimental groups was significantly higher than in the SHAM and CONTROL groups. Furthermore, the 660nm and 808nm wavelengths increased serum vitamin D levels significantly. The most successful outcomes were observed in clinical scoring, dead bone count, epithelial cell regeneration, and bone density in the 660nm and 808nm wavelength groups. Conclusions: The combined use of lasers at 660nm and 808nm wavelengths may yield successful results in treating MRONJ.

Effect of 532nm and 589nm Diode-Pumped Solid-State (DPSS) Lasers with Different Doses on Concentration of Total Protein and Albumin in Vitro.

To test the effects of Low-level laser irradiation at 532nm and 589nm with different doses and exposure times on total protein and albumin in blood plasma. This experimental study was conducted from November 2021 to April 2022 at Mustansiriyah University, Baghdad, Iraq, and comprised blood samples from healthy adults. The samples were stored in tubes containing anticoagulant ethylenediaminetetraacetic acid. Photoradiation was managed using green laser 532nm and yellow laser 589nm diode-pumped solid-state lasers with different doses. For total protein test and albumin test, each sample was divided into 3 equal aliquots. The first was control without radiation, the second was irradiated by a laser at 532nm, and the third was irradiated at 589nm with 30J/cm², 50J/cm², 70J/cm² and 90 J/cm² doses of irradiation. All samples were examined by using a spectrophotometer device. Data was analysed using SPSS 25. There were 24 samples from healthy adults in all.The most significant difference in total protein concentration occurred at dose 70J/cm² for both wavelengths compared to the controls (p<0.05). When this optimal dose was applied to the albumin test, a clear decrease in the albumin concentration was found for both 532nm and 589nm lasers (p<0.05). At wavelengths of 532nm and 589nm, the laser light induced processes that caused a reduction in total protein and albumin.

Influence of Laser Energy on the Structural and Optical Properties of Sn Nanoparticles produced with Laser-Induced Plasma

This study aimed to investigate the structure and optical properties of Sn nanostructures. Thin tin (Sn) films were deposited on glass substrates using the pulsed laser deposition method. Nd:YAG laser with fundamental wavelengths of 532 nm and 1064 nm was used to create Sn nanostructures with varying energies of 400 mJ to 700 mJ and the same frequency of 6 Hz. The tin powder was compressed into a disc with a one-centimetre diameter to serve as a sample. The X-ray diffraction (XRD) pattern showed a crystalline structure with several Sn nanostructures peaks at various energies (400–700 mJ). The results revealed a crystalline size of 65.90 nm and 86.55 nm at 700 mJ, while the size was 40.19 nm and 17.19 at 400 mJ for the given wavelengths (532nm and 1064 nm), respectively. The appearance of Sn nanostructures and the aggregation of, particularly in the form of cauliflower, were revealed in Field emission scanning electron microscopy (FE-SEM) images. The results of the dispersive energy X-ray spectroscopy (EDS) analysis showed that various amounts of tin, carbon, and oxygen were present. Additionally, the optical characteristics were investigated of each film using absorbance spectra, which covered a range of wavelengths from 190 to 1100 nm. As the laser power increased, the band gap energy values in the optical properties decreased, falling into the ranges of 3.06 to 1.65 eV and 3.22 to 1.82 eV at 1064nm and 532nm, respectively.

Comparison of optical trapping wavelengths for nanoscopic diamonds containing nitrogen-vacancy centers

In this article, we explore the effect of two different infrared (IR) laser wavelengths on the optical properties of trapped nano-diamonds containing high-density ensembles of nitrogen vacancy (NV) centers. We investigate 975 nm and 1064nm wavelengths for trapping lasers and find that NV photoluminescence quenching is more prominent for 1064nm illumination than for 975 nm illumination when simultaneously excited with a 532 nm laser. In order to understand the underlying mechanism, we develop a rate-equation-based model that takes into account various transition probabilities. The model suggests that the findings cannot be explained only by imposing modification of the NV charge-state ratio under varied illumination wavelengths, and, thus, we speculate that the effective ionization and recombination rates associated with NV charge states for the studied samples are highly wavelength-dependent in the probed regime. Importantly, the results demonstrate that 975 nm laser is desirable for optical trapping of NV-diamonds, especially for NV-based sensing applications.

Application of COMSOL Multiphysics for Fiber Beam Profiling

Fiber optic beam profiling is essential across scientific and engineering realms, demanding precise characterization of light beams for optimized system performance, accurate alignment, and efficient resource utilization. This study employs COMSOL Multiphysics to comprehensively analyze single-mode and multimode fiber beam profiles, encompassing diverse parameters such as wavelengths and modal distributions. The investigation of beam profiles is based on 850nm, 1310nm and 1550nm wavelengths; with three different modes (1, 5, and 20). COMSOL Multiphysics enhances beam profiling by providing precise numerical techniques, multiphysics modeling, and flexible parameter analysis. Its user-friendly interface facilitates efficient research, while validation and innovative possibilities underscore its value in photonics advancements. The research addresses the need for advanced profiling techniques, offering a robust methodology that captures intricate modal interactions and boundary conditions. Key findings include distinctive beam waist evolution, mode distribution patterns, and beam shaping behaviors, impacting data transmission, medical procedures, and manufacturing. By integrating computational power, this study advances our understanding of photonics, providing practical insights for future fiber optic technologies and their broader implications.

Broadband free space 2 × 4 90° optical hybrid for satellite laser communication.

We design a broadband free space 2×4 90° optical hybrid over a spectral window of 1000-1200nm and 1470-1650nm and verify the feasibility of the scheme experimentally. The hybrid consists of three broadband polarization beam splitters, an achromatic λ/4 wave plate, and three achromatic λ/2 wave plates. The fabricated hybrid exhibits a good quadrature phase response with an interchannel imbalance of 0.93-1.07 and a low phase deviation of less than 0.2° under the typical communication wavelengths of 1064nm and C-band. The experimental results of the heterodyne method show that the proposed hybrid can effectively solve the wavelength incompatibility problem in satellite laser communication and realize interconnection at different wavelengths. The designed hybrid (without coupling) has a measured insertion loss of no more than 7.34dB at 1064nm and C-band. A high-speed transmission experiment with BPSK format has been conducted to verify the performance of the assembled device.

Development and suborbital validation of technologies for direct imaging of nearby exoplanetary systems in reflected visible wavelengths

Primarily through indirect observational techniques, the existence of thousands of exoplanetary systems has been confirmed. However, we still do not have an image of an exoplanetary system in reflected visible light. This is important because planetary systems as old as the solar system (∼5 G yr) have cooled to near equilibrium and are thus no longer as bright as the systems being detected by current infrared coronagraphs. Furthermore, the visible bandpass contains valuable information about aerosols, hazes, and clouds that are unavailable to infrared investigations.Our research group has transitioned key technologies that are necessary for direct imaging of exoplanets and their environments from laboratory to near space using suborbital platforms. Two of our sounding rocket experiments, called Planetary Imaging Concept Testbed Using a Rocket Experiment (PICTURE) and Planet Imaging Coronagraphic Technology Using a Reconfigurable Experimental Base (PICTURE-B), matured a 0.5m diameter Gregorian telescope, a (600nm to 750nm) visible nulling coronagraph (VNC), a 1024 channel deformable mirror (DM) and a fine pointing system.Following up on these rocket experiments, in 2019 we flew a high-altitude balloon called Planetary Imaging Concept Testbed Using a Recoverable Experiment - Coronagraph (PICTURE-C). It carried a telescope employing a 0.6m diameter Off Axis Parabolic (OAP) primary mirror, a vector vortex coronagraph (VVC), a 97-channel low order and a 1024 element high order DM operating in the 540nm to 660nm wavelength range. Like the rocket experiments, the first balloon flight demonstrated a 5 milliarcseconds (mas) fine pointing capability and the space worthiness of the coronagraph.The latest flight of PICTURE-C occurred on September 28 2022. It was designed to obtain the first high contrast (∼10−6) image of a debris disk, a circumstellar ring produced by the sublimation of cometary material and collisions among asteroids, comets and Kuiper-belt analogs, in reflected visible light. The experiment achieved 1 mas root mean square (RMS) fine pointing stability. Even though unanticipated transient vibrations prevented PICTURE-C from attaining its science goals, the conronagraph demonstrated 4×10−6 contrast over 540nm to 660nm (20% bandwidth).

Study of the Optical Properties of Silver Nanoparticles Prepared by the Pulsed Laser Ablation Technique in Water

Pulsed laser ablation technique (neodymium Yak pulsed laser) was used to prepare silver nanoparticles from silver sheet target with purity (99.99%) different laser wavelengths (532nm,1064nm, 1320nm) and different energies(600mj,800mj ,1000mj) were used in the preparation .The laser frequency was (6Hz) and the number of pulse was 1000 pulse. The optical properties of the nanoparticles were studied with UV-VISIBLE spectroscopy. The absorption spectra showed the appearance of sharp peaks as a result of surface Plasmon resonance at different wavelengths, these peaks appeared at wavelengths (400nm) for lasers with wavelength (532nm) and different energies ,while peaks appeared at wavelengths (400nm) for lasers with wavelength (1064nm) ,and finally wavelength at which peaks appeared was (409nm) for lasers with wavelength (1320nm).

Comparative study of soft tissue surgery by visible and infrared laser radiation.

To compare the cutting properties of lasers with different wavelengths (445nm, 532nm and 808nm) used in cutting blood-rich tissues.Porcine myocardial tissue was cut using 2.3-15 W laser radiation in contact and non-contact modes with an optical fiber or focusing handpiece. The cut depth and coagulation zone width were determined histologically.The 445-nm laser achieved the greatest cut depth for all cutting parameters (p < 0.01). The blue laser gave the smallest coagulation width to cut depth ratio.Results of the study are consistent with the assumption that a 445nm blue laser may have better cutting properties than green and infrared lasers due to the high absorption of radiation at this wavelength in hemoglobin and, consequently, in the biological blood-rich tissue.

Analysis of Vegetation Index of Oil Palm Plants infected with Ganoderma Disease

One of the characteristics of Ganoderma disease is that it is asymptomatic, visual symptoms appear when the condition of the plant is severe so early detection and identification become a fundamental problem. This study aims to identify Ganoderma disease by analyzing the vegetation index NDVI, GNDVI, and SAVI based on the reflectance value of oil palm plant images recorded with a UAV vehicle equipped with a multispectral sensor 3 bands red (Red), green (Green), infrared (Near Infra Red) at 660nm, 550nm and 850nm wavelengths. The software used is Mission Planner, Agisoft Meta Shape, Mapir Camera Control, ArcGIS 10.5, and ENVI 5.3. The research location is in an oil palm plantation in Pabatu in an area of 247ha planted in 2004 and 2005. The results of observations of Ganoderma disease reached 24.1%. The reflectance value of infected plants was lower than that of healthy plants with a ratio of 56.7%, 66.5%, and 44.7% in the R, G, and NIR bands. The reflectance value consistently decreases with an increasing attack of Ganoderma disease. The NDVI, GNDVI, and SAVI values in healthy plants were 0.29; 0.34, and 0.21, and in infected plants the values were lower. Vegetation index parameters can be important information to detect and identify Ganoderma disease attacks.

Ex Vivo Evaluation of the Efficacy of Photodynamic Therapy in Eliminating Enterococcus faecalis from Dentinal Tubules by Confocal Laser Scanning Microscopy

IntroductionThe aim of the present study was to investigate ex vivo by confocal laser scanning microscopy the antibacterial effect of photodynamic therapy (PDT) on dentinal tubules in the apical 5 mm of human mandibular premolars contaminated with Enterococcus faecalis. MethodsThirty-four teeth were standardized to 20 mm and foraminal anatomic diameters using a #20 K-file (Dentsply Maillefer). Samples were contaminated for 21 days and divided into the following 3 experimental groups (n = 10): the PDT group (instrumented canals and PDT), the passive ultrasonic irrigation (PUI) group (instrumented canals and PUI), and the PUI-PDT group (instrumented canals, PUI, and PDT), along with a control group (n = 4) (noninstrumented canals). The canals in the experimental groups were instrumented with ProTaper Next (Dentsply Maillefer) up to X3 and rinsed with EDTA and sodium hypochlorite. The photosensitizer used was 0.01% methylene blue with a preirradiation time of 5 minutes and a diode laser with 4 J energy and a 660-nm wavelength. Cross sections were made 5 mm from the apex of all samples, which were analyzed using confocal laser scanning microscopy. The results were analyzed using the Shapiro-Wilk and Kruskal-Wallis (Dunn) tests. ResultsThere was a lower percentage of live bacteria in the PUI-PDT group, with a statistical difference compared with the control and PDT groups (P < .05). There was no statistical difference in the percentage of live bacteria between PUI-PDT and PUI (P > .05). ConclusionsIt was concluded that the PUI-PDT association was most effective in disinfecting root canals compared with the control group and PDT.

Design and Performance Evaluation of Free Space Optical Communication Link in Zaria, Nigeria

Free Space Optical Communication (FSOC) is an optical technology with a great chance to complement traditional wireless communication technologies. It offers essential advantages compared to Radio Frequency (RF), such as low power consumption, no frequency restrictions, no electromagnetic interference, security, and a significant increase in bandwidth. Similarly, they have proven a worthy substitute for fiber optics with notable advantages. FSOC systems are usually installed above ground level and are therefore exposed to prevailing weather conditions such as haze, fog, rain, etc. which negatively affect the optical signal transmission. There is a shortage of research on using FSO systems in tropical regions. For this reason, accurate free space optical communication channel modeling helps telecommunication operators to engineer and appropriately manage their networks. Therefore, this research work developed Free Space Optical Communication Channel Model to mitigate the effects of atmospheric attenuations by estimating the specifically induced attenuation caused by both haze and rainfall rates on the FSOC link in the Zaria geographical area using two years of measured visibility data and rainfall rates data of the study location obtained from Nigerian Meteorological (NIMET) agency, Zaria station, locatedat the Nigeria College of Aviation Technology (NCAT) Zaria and Center for Energy Research and Training (CERT), Ahmadu Bello University (ABU), Zaria. The performance of the FSOC system is analyzed and evaluated through Link Margin (LM) analysis by using the design specifications of a commercial optical transceiver (TereScope 5000). The haze-induced attenuation obtained at 850nm, 950nm, and 1550nm is 5.934dB, 6.402dB, and 3.152dB respectively. Therefore, the result shows that the 1550 nm wavelength has minimum haze-induced attenuation compared to 850nm and 950nm at a propagation link distance of 6km. Furthermore, from the results of the performance evaluation of the LM analysis for the combined effects of Geometrical Attenuation (Gatt), Haze-Induced Attenuation (HIA), and Rain-Induced Attenuation (RIA), the result shows that operating a 1550nm wavelength in transmission power greatly improves optical transmission when compared with 850nm and 950nm wavelengths. Generally, the overall outcome of the research concludes that the free space optical communication system has the robustness to handle successful wireless communication during the worst weather conditions in Zaria throughout the year for a link range of up to 6km

Lower eyelid blepharoplasty combined with ultrasound-guided percutaneous diode laser lipolysis: evaluating effectiveness with long-term outcome.

Laser lipolysis may be considered for selective removal of excess orbital fat via minimally invasive lower blepharoplasty. To control the energy delivery to a precise anatomic location while avoiding complications, ultrasound guidance can be utilized. Under local anesthesia, a diode laser probe (Belody, Minslab, Korea) was introduced percutaneously to the lower eyelid. The tip of the laser device and changes in orbital fat volume were carefully controlled with ultrasound imaging. A 1470-nm wavelength was used for orbital fat reduction (maximal energy 300J), and a 1064-nm wavelength was used to tighten the lower eyelid skin (maximal energy 200J). From March 2015 to December 2019, a total of 261 patients underwent ultrasound-guided diode laser lower blepharoplasty. The procedure took 17min on average. Total energy of 49J-510J (average = 228.31J) was delivered in 1470-nm wavelengths or 45-297J (average = 127.68J) was delivered in 1064-nm wavelengths. Most patients were very satisfied with their results. Fourteen patients experienced complications, including nine cases of transient hypesthesia (3.45%), and three skin thermal burns (1.15%). However, these complications were not observed after strict control of the energy delivery below 500J for each lower lid. Improvement in lower eyelid bags can be achieved using a minimally invasive approach in selected patients with ultrasound-guided laser lipolysis. It is a fast and safe procedure that can be performed in the outpatient setting.

Estimate the Attenuation and Simulation of dispersion Gaussian pulses propagation in a Single Mode Optical Fiber

we studied Attenuation in Fiber Optics, we used two type of Fibers (Plastic and glass) with length (0.5,5,20m) and (1,20,100m) respectively and used two wavelength laser (660nm, 850nm), we found attenuation increase with 850nm wavelength and 660nm wavelength are the best for the plastic fiber optics, in addition the attenuation which occur from axial gap, axes rotation, inclination angle, transversal displacement are investigated. Influence three values of linear dispersion on Pulse propagation along fiber at seam distance is investigated by simulation using Fourier Method using MATLAB.

Investigative analysis of selected FSO models with varying wavelengths for tropical weather

In this paper, an investigation of some selected Mie and geometric Scattering models for free space optical (FSO) communication was done on available atmospheric data in Nigeria. The Kim and Kruse models have been established for the temperate region. In this work, the models were examined using the visibility data from the year 2008 to 2019. The models were examined under the 2% and 5% transmission threshold and under the wavelengths 780nm, 850nm, 1100nm, and 1550nm. The results indicates a higher attenuation at 780nm, supporting what is available in literature. The Suriza et al, ITU-R(Carbonneau) and Gailani et al &nbsp;models were investigated using the rain intensity data. The Suriza et al model indicates a reduced attenuation compared to the other two models.

Preparation of YAG nanopowders and ceramics via coprecipitation: Effects of treatment modes of precipitates

Effects of treatment modes of precipitates in the coprecipitation method on the resulting YAG nanopowders and ceramics are investigated. Three treatment modes for precipitates, namely, single water washing, water–ethanol washing, and water washing–ethanol immersion, are conducted to prepare the YAG nanopowders. The average particle size (∼62 nm) and distribution (mainly ranging from 30 to 110 nm) of the powders obtained by the three modes are similar. However, the dispersity of the three powders shows large differences. The nanopowder obtained via water washing–ethanol immersion possesses optimal dispersity without any agglomeration, whereas that obtained via single water washing comprises substantially hard agglomerations. The relative density, Vickers hardness, and optical in-line transmittance of the ceramics prepared via water washing–ethanol immersion, respectively, reach 99.85%, 14.1 ± .4 GPa, and 77.8% at 1064-nm wavelengths after spark plasma sintering. These results are markedly superior to those of the ceramics prepared using the two other modes (97.43%, 6.8 ± .7 GPa, and 17.2% at 1064-nm wavelengths and 98.97%, 10.2 ± .5 GPa, and 47.8% at 1064-nm wavelengths, correspondingly). Therefore, water washing–ethanol immersion is a sensible and advisable treatment mode of precipitates for preparing YAG nanopowder and ceramics via coprecipitation.

Progression pattern of myopic maculopathy according to the severity of diffuse chorioretinal atrophy and choroidal thickness

This observational cohort study aimed to evaluate the progression pattern of diffuse chorioretinal atrophy (DCA) according to its severity. Highly myopic eyes with DCA were graded according to its extent in the 532-nm (green) and 633-nm (red) wavelengths images of the Optos ultra-widefield scanning laser ophthalmoscope at baseline: grade 1 and 2 were defined when increased reflectance at peripapillary region, not beyond the fovea, were observed in red laser image only and in both laser images, respectively; grade 3 and 4 were defined when increased reflectance beyond the fovea were observed in red laser image only and in both laser images, respectively. A total of 307 eyes (221 patients) were included, and progression of myopic maculopathy during follow-up of ≥ 3 years was evaluated. The mean visual acuity and subfoveal choroidal thickness (CT) differed among DCA grades (P = 0.015 and P < 0.001); a higher DCA grade had worse visual acuity and thinner choroid. During follow-up, development of patchy atrophy (PA) was observed in 3.2%, 5.5%, 12.8%, and 23.2% (P < 0.001), while changes in lacquer crack (LC) and/or development of myopic macular neovascularization were observed in 20.6%, 29.1%, 33.3%, and 15.8% (P = 0.061) of 63, 110, 39, and 95 eyes with DCA grade of 1, 2, 3, and 4 at baseline, respectively. New LC formation tended to occur in eyes with thicker CT at baseline compared to PA development and progression of pre-existing LC. In highly myopic eyes with DCA, progression pattern of myopic maculopathy is different according to its severity and CT at baseline. Grading based on separated wavelength images of ultra-widefield scanning laser ophthalmoscope is useful to evaluate the severity and prognosis of DCA in Asian patients with high myopia.

Most used photobiomodulation dosimetry parameters to treat oral mucositis after preconditioning for hematopoietic stem cell transplantation: systematic review and meta-analysis.

Parameter reproducibility in photobiomodulation therapy (PBMT) is still scarce in literature for the management of oral mucositis (OM). This study aimed to identify the most used PBMT dosimetry parameters (DP) and their efficacy in OM management after preconditioning for hematopoietic stem cell transplantation (HSCT). This research was conducted according to the PRISMA guidelines. The search for primary studies was in PubMed/MEDLINE, Web of Science, Embase, BVS, and Cochrane Library. Gray literature was verified on BDTD-Ibict and Open Gray. A total of 1044 studies were identified. Nine met the eligibility criteria for qualitative assessment and 7 for meta-analysis. The studies involved 396 patients submitted to preconditioning for HSCT, 211 with PBMT and 185 without PBMT in the OM management. The WHO scale was the most used to assess OM degree. The most used parameters were 660-nm wavelength, 40-mw power, 0.16-J energy, 1-W/cm2 power density, 4-J/cm2 energy density, and 0.04-cm2 spot size. The meta-analysis demonstrated that PBMT decreased the severity of OM, with a protection factor 20% higher than the control group (without PBMT), and when the parameters are similar to the DP mentioned, the protection factor increases to 94%. These most used DP with similarity seem to be a therapeutic strategy for the management of OM in this population.

Assessment of Healing and Pain Response at Mandibular Third Molar Extraction Sites with and Without Pre- and PostOperative Photobiomodulation at Red and Near-Infrared Wavelengths: A Clinical Study.

Background:Photobiomodulation (PBM), formerly known as low-level laser therapy, has been successfully used for its anti-inflammatory and analgesic properties in postoperative care. It is also known to have a positive effect on healing and regeneration, at an appropriate power and wavelength.Aim:The main objective was to assess the effect of preoperative as well a postoperative irradiation with low power of 100 milliwatts (mW) and 810-nanometer (nm) (near-infrared) and 660-nanometer(nm) (red) wavelengths on healing as well pain at mandibular third molar extraction sockets.Methodology:Twenty-six patients who were scheduled for mandibular third molar extractions were enrolled in the study and were randomly assigned to the experimental and control group. The experimental group consisted of 13 patients who were subjected to 810-nm irradiation at 100 MW at the site immediately before and after the extraction was completed. In addition, they also received a transcutaneous irradiation of 660-nm wavelength light 1-day postoperatively. The control group received no irradiation immediately after postextraction or the day after. Pain and healing were assessed using the visual analog scale and Turnbull and Howley's Index for soft-tissue healing on the 7th and the 21st days. Data were analyzed using the Mann–Whitney test.Results:The results showed clinically significant improvements in healing index scores and pain scores of the experimental group than the control group (P < 0.0001).Conclusion:PBM at an appropriate wavelength is a potential tool for the management of pain and accelerating healing at mandibular third molar extraction sites.

Photobiomodulation Improves the Inflammatory Response and Intracellular Signaling Proteins Linked to Vascular Function and Cell Survival in the Brain of Aged Rats.

Photobiomodulation is a non-pharmacological tool widely used to reduce inflammation in many tissues. However, little is known about its effects on the inflammatory response in the aged brain. We conducted the study to examine anti-inflammatory effects of photobiomodulation in aging brains. We used aged rats (20months old) with control (handled, laser off) or transcranial laser (660nm wavelength, 100 mW power) treatments for 10 consecutive days and evaluated the level of inflammatory cytokines and chemokines, and the expression and activation of intracellular signaling proteins in the cerebral cortex and the hippocampus. Inflammatory analysis showed that aged rats submitted to transcranial laser treatment had increased levels of IL-1alpha and decreased levels of IL-5 in the cerebral cortex. In the hippocampus, the laser treatment increased the levels of IL-1alpha and decreased levels of IL-5, IL-18, and fractalkine. Regarding the intracellular signaling proteins, a reduction in the ERK and p38 expression and an increase in the STAT3 and ERK activation were observed in the cerebral cortex of aged rats from the laser group. In addition, the laser treatment increased the hippocampal expression of p70S6K, STAT3, and p38 of aged rats. Taken together, our data indicate that transcranial photobiomodulation can improve the inflammatory response and the activation of intracellular signaling proteins linked to vascular function and cell survival in the aged brain.